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1da177e4 LT |
1 | /* |
2 | * $Id: mtdblock_ro.c,v 1.19 2004/11/16 18:28:59 dwmw2 Exp $ | |
3 | * | |
4 | * (C) 2003 David Woodhouse <dwmw2@infradead.org> | |
5 | * | |
6 | * Simple read-only (writable only for RAM) mtdblock driver | |
7 | */ | |
8 | ||
9 | #include <linux/init.h> | |
10 | #include <linux/slab.h> | |
11 | #include <linux/mtd/mtd.h> | |
12 | #include <linux/mtd/blktrans.h> | |
13 | ||
14 | static int mtdblock_readsect(struct mtd_blktrans_dev *dev, | |
15 | unsigned long block, char *buf) | |
16 | { | |
17 | size_t retlen; | |
18 | ||
19 | if (dev->mtd->read(dev->mtd, (block * 512), 512, &retlen, buf)) | |
20 | return 1; | |
21 | return 0; | |
22 | } | |
23 | ||
24 | static int mtdblock_writesect(struct mtd_blktrans_dev *dev, | |
25 | unsigned long block, char *buf) | |
26 | { | |
27 | size_t retlen; | |
28 | ||
29 | if (dev->mtd->write(dev->mtd, (block * 512), 512, &retlen, buf)) | |
30 | return 1; | |
31 | return 0; | |
32 | } | |
33 | ||
34 | static void mtdblock_add_mtd(struct mtd_blktrans_ops *tr, struct mtd_info *mtd) | |
35 | { | |
36 | struct mtd_blktrans_dev *dev = kmalloc(sizeof(*dev), GFP_KERNEL); | |
37 | ||
38 | if (!dev) | |
39 | return; | |
40 | ||
41 | memset(dev, 0, sizeof(*dev)); | |
42 | ||
43 | dev->mtd = mtd; | |
44 | dev->devnum = mtd->index; | |
45 | dev->blksize = 512; | |
46 | dev->size = mtd->size >> 9; | |
47 | dev->tr = tr; | |
48 | if ((mtd->flags & (MTD_CLEAR_BITS|MTD_SET_BITS|MTD_WRITEABLE)) != | |
49 | (MTD_CLEAR_BITS|MTD_SET_BITS|MTD_WRITEABLE)) | |
50 | dev->readonly = 1; | |
51 | ||
52 | add_mtd_blktrans_dev(dev); | |
53 | } | |
54 | ||
55 | static void mtdblock_remove_dev(struct mtd_blktrans_dev *dev) | |
56 | { | |
57 | del_mtd_blktrans_dev(dev); | |
58 | kfree(dev); | |
59 | } | |
60 | ||
61 | static struct mtd_blktrans_ops mtdblock_tr = { | |
62 | .name = "mtdblock", | |
63 | .major = 31, | |
64 | .part_bits = 0, | |
65 | .readsect = mtdblock_readsect, | |
66 | .writesect = mtdblock_writesect, | |
67 | .add_mtd = mtdblock_add_mtd, | |
68 | .remove_dev = mtdblock_remove_dev, | |
69 | .owner = THIS_MODULE, | |
70 | }; | |
71 | ||
72 | static int __init mtdblock_init(void) | |
73 | { | |
74 | return register_mtd_blktrans(&mtdblock_tr); | |
75 | } | |
76 | ||
77 | static void __exit mtdblock_exit(void) | |
78 | { | |
79 | deregister_mtd_blktrans(&mtdblock_tr); | |
80 | } | |
81 | ||
82 | module_init(mtdblock_init); | |
83 | module_exit(mtdblock_exit); | |
84 | ||
85 | MODULE_LICENSE("GPL"); | |
86 | MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>"); | |
87 | MODULE_DESCRIPTION("Simple read-only block device emulation access to MTD devices"); |